In the field of hydrocarbon production, it is sometimes necessary to block the wellbore, e.g. to seal of part of the well. In substantially vertical wells, this may be done by setting some kind of plug and pouring cement into the well. When the cement cures, a plug in the wellbore is created. Depending on the materials used for creating the plug, it may be possible to drill through the plug to restore the flow path. Alternatively, the plug may be a permanent plug.
However, in deviated wells, it is not possible to cast a plug by simply pouring cement into the borehole. In deviated wells, such as wells having an inclination close to horizontal, the process of casting a plug is much more complicated.
Injection of a fluid such that the injected fluid fills up all of the available space of a section of the wellbore, either open or cased, is especially challenging in a deviated well inter alia due to gravity. If a plug is set in the well and a fluid is injected above the plug, the fluid will naturally level out in the well above the plug. If the well is highly deviated, it is practically impossible to make the fluid fill out a cross section of the wellbore. If the fluid is to fill out the cross section of the well over a section of the well, e.g. if a plug with a certain length is required, the task becomes even more difficult.